Refrigerator and deodorizer producing ozone by high-voltage discharge

ABSTRACT

A refrigerator includes a deodorizer disposed in a cold air circulation path for deodorizing an atmosphere in the refrigerator. The deodorizer includes discharging means for producing ozone and ultraviolet rays by means of high-voltage discharge and a photocatalyst module for decomposing an odor component and injurious matter contained in the atmosphere by means of photocatalyst.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a refrigerator provided with adeodorizer disposed in a circulation path for cold air so that thecirculated cold air is deodorized and further to a deodorizer fordeodorizing air by decomposing odor component and/or injurious mattercontained in the air.

[0003] 2. Description of the Related Art

[0004] In conventional household refrigerators, a platinum catalyst isdisposed near a defrosting heater so that odor component contained inair is adsorbed. The heater is energized in a defrosting operation sothat the adsorbed odor component is thermally decomposed, whereby theinterior of the refrigerator is deodorized. However, a deodorizerproviding a higher deodorizing performance has been required in orderthat an offensive odor in the refrigerator may be eliminated and may beprevented from scenting other food.

[0005] Recent refrigerators have been provided with two evaporators fora cold-storage compartment and a freezing compartment respectively. Thehumidity in the cold-storage compartment is set to be higher using thetwo evaporators so that an improvement is achieved in the preservationof freshness of food. However, when the humidity is increased in thecold-storage compartment, odor tends to become stronger and bacteriatend to increase.

[0006] In view of the foregoing circumstances, a deodorizer usingoxidation of ozone has been equipped in refrigerators. However, odorcomponent cannot sometimes be decomposed completely even by theoxidation of ozone such that intermediate products are produced.

[0007] Furthermore, odor component is oxidized by a photocatalyst. Forexample, this is achieved by irradiating ultraviolet rays onto aphotocatalyst material such as titanium oxide. This method can obtain alarger oxidizing force than from ozone. However, a fluorescent lamp isrequired to irradiate ultraviolet rays onto the photocatalyst material.Since the fluorescent lamp contains mercury, consideration is necessaryso that environmental load is not increased when the refrigerator ordeodorizer is disposed of. Thus, the deodorizer employing thephotocatalyst entails a problem of handling the fluorescent lamp in thecase of disposition thereof.

[0008] A demand for eliminating odor component and injurious mattercontained in the air in a residence has been increased with improvementin residentail gastightness and chronicity in contamination of outdoorair. In particular, a demand for eliminating cigarette smoke, metabolicodor or volatile organic compound (VOC) such as formaldehyde containedin building material has been increased. The prior art has provided twomajor methods of eliminating odor component and injurious matter. In onemethod, an adsorbent such as activated charcoal is used to eliminate theodor component. In the other method, odor component is caused to reactupon drugs so that the nature of the odor component is changed.

[0009] In the aforesaid first method, however, the adsorbent has adefinite limit in an amount of odor component to be adsorbed.Accordingly, the adsorbent needs to be periodically replaced by a newone. Further, even before the adsorbing performance saturates, the odorcomponent which has been once adsorbed by the adsorbent is released intoair again at a final stage of the service life of the adsorbent. In theother method, the drug upon which the odor component is caused to reactneeds to be supplemented or replaced, resulting in complicatedness inmaintenance. Further, control for adjusting the concentration of thedrug released into air is difficult.

[0010] A catalytic reaction with a high deoxidation potential isrequired in order that an injurious gas component such as formaldehydemay be eliminated. For example, in decomposition by oxidation with useof ozone, the injurious gas component is only converted into anintermediate product due to decomposition but cannot completely beeliminated for harmlessness. Further, for example, formaldehyde or thelike can be decomposed by irradiating ultraviolet rays onto aphotocatalyst material such as titanium oxide. Irradiation ofultraviolet rays necessitates a fluorescent lamp. However, thefluorescent lamp contains mercury. Accordingly, a due consideration isnecessary for adverse effect on environment when the fluorescent lamp isdisposed of. Thus, conventional deodorizers using the fluorescent lampentail a problem of dealing for disposition.

SUMMARY OF THE INVENTION

[0011] Therefore, an object of the present invention is to provide arefrigerator with a deodorizer which can achieve an improved deodorizingfunction and which requires no special handling when disposed of.

[0012] Another object of the invention is to provide a deodorizer whichcan eliminate injurious gas components etc. without requiringsupplementation or replacement of drug and any special dealing fordisposition.

[0013] The present invention provides a refrigerator in which adeodorizer is provided in a cold air circulation path for deodorizing anatmosphere in the refrigerator, the deodorizer comprising dischargingmeans for producing ozone and ultraviolet rays by means of high-voltagedischarge and a photocatalyst module for decomposing an odor componentand injurious matter contained in the atmosphere by means ofphotocatalyst.

[0014] According to the above-described construction, the ultravioletrays are produced by the high-voltage discharge of the dischargingmeans. Further, when subjected to the ultraviolet rays, thephotocatalyst module performs a photocatalytic reaction. As a result,the odor component contained in the circulated cold air is decomposed byoxidation to thereby be eliminated. Thus no special handling is requiredin the case of disposition of the refrigerator or the deodorizer sincethe ultraviolet rays can be produced without using a fluorescent lamp.

[0015] Furthermore, ozone is also produced by the high-voltagedischarge. Accordingly, the odor component in the refrigerator isfurther decomposed by the oxidation of the ozone. Additionally, theproduced ozone is diffused into the interior of the refrigerator withthe circulated cold air such that an ozonic atmosphere is formed. Sincethe ozonic atmosphere provides an antibacterial action for food storedin the refrigerator, the freshness of the food can be maintained.

[0016] In a preferred form, the deodorizer further comprises ozonedecomposing means for decomposing the ozone produced by the dischargingmeans, and the ozone decomposing means is disposed at a downstream sideof at least the discharging means and the photocatalyst module withrespect to a direction in which the cold air flows. The ozone producedby the high voltage discharge is decomposed by the ozone decomposingmeans in the aforesaid construction. Consequently, the ozonicconcentration can be prevented from an excessive increase andaccordingly, the user can be prevented from having a smell of ozone whenopening the door of the refrigerator. Further, since decomposition ofozone tends to produce more active oxygen, oxidation can further befacilitated and the deodorizing efficiency can further be improved.

[0017] In another preferred form, the refrigerator further comprises aheat exchanger having a cold air inlet, and the ozone decomposing meansis disposed in the cold air inlet of the heat exchanger. When ozoneproduced by the deodorizer is circulated so as to pass through anevaporator, there is a possibility that the evaporator and piping mayadversely be affected. When the ozone decomposing means is disposed inthe cold air inlet of the heat exchanger in view of the aforesaidproblem, ozone is decomposed before the circulated cold air is takeninto the heat exchanger. Consequently, inner components of therefrigerator can be prevented from being adversely affected by theozone.

[0018] In further another preferred form, the refrigerator furthercomprises control means for controlling the deodorizer so that thedischarging means discharges electricity when cold air is circulated inthe refrigerator. Upon circulation of cold air, the cold air containingan odor component is caused to flow into the deodorizer so that the coldair is deodorized. Consequently, the deodorization can be performed moreefficiently.

[0019] In further another preferred form, the discharging means includestwo electrodes and the photocatalyst module is disposed between theelectrodes of the discharging means. Since the ozone produced by thedischarging means is efficiently irradiated onto the photocatalystmodule, the photocatalytic reaction can be facilitated.

[0020] The refrigerator preferably further comprises a refrigerator bodyand the deodorizer is attached to and detached from the refrigeratorbody. When the deodorizer is detached from the refrigerator body,substances resulting from decomposition and adherent to portions of thedeodorizer can easily be removed.

[0021] At least the discharging means of the deodorizer is preferablypowered by a battery. Since the deodorizer is completely discrete fromthe refrigerator, the deodorizer can be disposed at any position in therefrigerator. Additionally, the deodorizer in accordance with theinvention can be provided in a refrigerator which does not have adeodorizing function.

[0022] The invention further provides a deodorizer comprising a blowingfan, discharging means for producing ozone and ultraviolet rays by meansof high-voltage discharge, the discharging means being disposed in ablowing path through which air is caused to flow by the blowing fan, aphotocatalyst module provided in the blowing path for decomposing anodor component and injurious matter contained in an atmosphere by meansof photocatalyst, and ozone decomposing means provided in the blowingpath for decomposing the ozone produced by the discharging means.

[0023] According to the above-described deodorizer, ozone andultraviolet rays are produced by the high-voltage discharge of thedischarging means disposed in the blowing path when the fan starts ablowing operation. The photocatalyst module disposed in the same blowingpath is subjected to the ultraviolet rays to cause the photocatalyticreaction such that the injurious gas component such as formaldehyde canbe decomposed by oxidation. Further, when ozone mixed with the odorcomponent is decomposed by the ozone decomposing means, the odorcomponent is decomposed by oxidization of the active oxygen. Thus, theodor component and the injurious component are decomposed to beeliminated by the oxidization by the ozone produced by the high-voltagedischarge and the photocatalytic reaction by the ultraviolet rays.Consequently, an adsorbent need not be replaced and drug need not besupplemented. Further, since the oxidation and the photocatalyticreaction are combined together, a larger number of types of odorcomponents can be decomposed. Additionally, since the ultraviolet raysare produced without use of fluorescent lamps, no special dealing fordisposition needs to be considered.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other objects, features and advantages of the present inventionwill become clear upon reviewing the following description of preferredembodiments, made with reference to the accompanying drawings, in which:

[0025]FIG. 1 is a longitudinally sectional side view of a deodorizerprovided in a refrigerator of a first embodiment in accordance with thepresent invention;

[0026]FIG. 2 is a longitudinally sectional side view of therefrigerator;

[0027]FIG. 3 is an enlarged view of a cold air path shown in FIG. 2;

[0028]FIG. 4 is a block diagram showing an electrical arrangement of therefrigerator;

[0029]FIG. 5 illustrates a refrigerating cycle employed in therefrigerator;

[0030]FIG. 6 is a graph showing the results of an experiment conductedby the inventors;

[0031]FIG. 7 is an enlarged longitudinally sectional side view of afirst cold air producing chamber of the refrigerator of a secondembodiment in accordance with the invention;

[0032]FIG. 8 is an enlarged longitudinally sectional side view of avegetable compartment of the refrigerator of a third embodiment inaccordance with the invention;

[0033]FIGS. 9A and 9B are perspective views of the vegetable compartmentwith a lower case being eliminated, showing the states before and afterattachment of the deodorizer respectively;

[0034]FIG. 10 is a view similar to FIG. 1, showing the refrigerator of afourth embodiment in accordance with the invention;

[0035]FIG. 11 is an exploded perspective view showing an electricaldischarge mechanism and a photocatalyst module;

[0036]FIG. 12 is a view similar to FIG. 1, showing the refrigerator of afifth embodiment in accordance with the invention;

[0037]FIG. 13 is a view similar to FIG. 1, showing the refrigerator of asixth embodiment in accordance with the invention;

[0038]FIG. 14 is a longitudinally sectional side view of the deodorizerof a seventh embodiment in accordance with the invention;

[0039]FIG. 15 is a schematic block diagram showing an electricalarrangement of the deodorizer;

[0040]FIG. 16 is a graph showing the results of an experiment conductedwith use of the deodorizer of the seventh embodiment by the inventors;

[0041]FIG. 17 is a view similar to FIG. 7, showing the deodorizer of aneighth embodiment in accordance with the invention; and

[0042]FIG. 18 is a perspective view of a part of the deodorizer shown inFIG. 17.

DETAILED DESCRIPTION OF EMBODIMENTS

[0043] A first embodiment of the present invention will be describedwith reference to FIGS. 1 to 6. Referring first to FIG. 2, arefrigerator of the first embodiment in accordance with the invention isschematically shown. The refrigerator comprises a body 1 formed into theshape of a generally rectangular box having a front opening. Therefrigerator body 1 is formed by assembling an outer casing 2 and aninner casing 3 and filling a space between the casings with aheat-insulating foam 4. A horizontal partition plate 5 made of asynthetic resin is fixed to an inner face of the inner casing 3. Thepartition plate 5 defines a cold storage compartment 6 in an upperinterior of the refrigerator body 1. A first door 7 is hingedly mountedon a front end of the cold storage compartment 6. The partition plate 5has on an upper face thereof a plurality of protrusions (not shown) onwhich a chilling case 8 is placed. The chilling case 8 is formed intothe shape of a container having upper and front openings. A cold airpath 9 is defined between the underside of the chilling case 8 and theupper face of the partition plate 5. A lid 10 is provided for openingand closing a front opening of the chilling case 8.

[0044] A support plate 100 is fixed to the inner face of the innercasing 3 so as to be spaced from the partition plate 5 under the latter.The partition plate 5 has an open front end through which cold air iscaused to flow from the cold storage compartment 6 side into a cold airpath 101 (a circulation path) defined between the partition plate 5 andthe support plate 100. A deodorizer 11 is provided in the cold air path101 as shown in FIG. 3. The construction of the deodorizer 11 will bedescribed in detail later. The support plate 100 has a rear end open toa vegetable compartment 13 (storage compartment). Cold air is caused toflow from the cold storage compartment 6 side through the cold air path101 and the deodorizer 11 into the vegetable compartment 13.

[0045] A heat-insulating partition plate 12 is fixed to the inner faceof the inner casing 3 so as to be spaced from the partition plate 5below the latter. The heat-insulating partition plate 12 is formed byenclosing styrene foam in a casing made of a synthetic resin. Thevegetable compartment 13 is thus defined between the heat-insulatingpartition plate 12 and the partition plate 5. The vegetable compartment13 communicates with the cold storage compartment 6 via the deodorizer11 located in the cold air path 101. Thus the vegetable compartment 13serves as a part of the cold storage compartment 6. A second door 14 ismounted on a front end of the vegetable compartment 13 so as to beslidable forward and rearward. A lower case 15 accommodated in thevegetable compartment 13 is formed into the shape of a container havingan upper opening. An upper case 16 is mounted on the lower case 15 so asto close an upper face of the lower case except a front end. The uppercase 16 is formed into the shape of a container having an upper opening.A lid 17 is mounted on the upper case 16 so as to close and open theupper opening of the upper case.

[0046] Referring to FIG. 2 again, a freezing compartment 19 is definedin the inner casing 3 so as to be located below the heat-insulatingpartition plate 12. Thus the freezing compartment 19 is thermallyisolated from the upper cold storage compartment 6 and vegetablecompartment 13. Upper and lower doors 20 and 21 are mounted on a frontend of the freezing compartment 19 so as to be slidable forward andrearward. Upper and lower freezing cases 22 and 23 are disposed in thefreezing compartment 19. A machine compartment 24 is defined in a lowerpart of the refrigerator body 1. A reciprocating compressor 25constituting a refrigerating cycle is provided in the machinecompartment 24. The compressor 25 includes a compressor motor 26 as adrive source. The compressor motor 26 is electrically connected througha drive circuit 27 to a control device 28 serving as control means andvoltage changing means as shown in FIG. 4. The control device 28comprises a microcomputer (not shown) as a main component and isprovided in the refrigerator body 1.

[0047] The compressor 25 has a discharge opening connected via acondenser 29 constituting the refrigerating cycle to an input port of apath valve 30 as shown in FIG. 5. The path valve 30 selectively opens afirst output port or a second output port on the basis of the normal orreverse rotation of a valve motor 31 (see FIG. 4). The valve motor 31 isconnected via the drive circuit 27 to the control device 28. The firstoutput port of the path valve 30 is connected via a first capillary tube32 to an entrance of a first evaporator 33 as shown in FIG. 5. The firstevaporator 33 has an exit connected to an entrance of a secondevaporator 34. The second evaporator 34 has an exit connected to asuction opening of the compressor 25. When the first output port of thepath valve 30 is open, refrigerant discharged from the compressor 25 issupplied into both of the first and second evaporators 33 and 34. Thepath valve 30 further has a second output port connected to an entranceof a second capillary tube 35. The second capillary tube 35 has an exitconnected between the exit of the first evaporator 33 and the entranceof the second evaporator 34. When the second output port of the pathvalve 30 is open, the refrigerant discharged from the compressor 25 issupplied only to the second evaporator 34.

[0048] Returning to FIG. 2 again, a first cold air producing chamber 36is defined in the rear of the vegetable compartment 13. The firstevaporator 33 is accommodated in the first cold air producing chamber36. The first cold air producing chamber 36 has a cylindrical cold airdischarge opening 37 and a cold air suction opening 38. The cold airdischarge opening 37 is inserted into the upper case 16.

[0049] A generally L-shaped duct cover 39 is fixed in the cold storagecompartment 6. The duct cover 39 is made of a synthetic resin and has aplurality of cold air discharge holes 40 open to the cold storagecompartment 6. The duct cover 39 constitutes a generally L-shaped coldair duct 41 in association with a rear wall of the inner casing 3. Theduct 41 has an upper end open to the interior of the cold storagecompartment 6 and a lower end communicating with the first cold airproducing chamber 36. A first fan motor 42 is provided in the first coldair producing chamber 36 and connected via the drive circuit 27 to thecontrol device 28. A first fan 43 (blower) is coupled with a rotationalshaft of the first fan motor 42 so that cold air is circulated throughthe following route upon rotation of the first fan 43. A first fan unit44 comprises the first fan motor 42 and the first fan 43. The first fanunit 44 and the first evaporator 33 constitute a first cooling unit 45.Cold air circulation path for the cold storage compartment 6 andvegetable compartment 13:

[0050] Part of air in the refrigerator is discharged from the first coldair producing chamber 36 through the cold air discharge opening 37 intothe upper case 16 to be discharged in front of the upper case 16 throughcold air flow holes 46 formed in the front end of the lid 17. The coldair further flows downward along the front of the lower case 15 and thenrearward along the underside of the lower case, returned through thecold air suction opening 38 into the cold air producing chamber 36. Inthis case, the interior air is cooled by the first evaporator into coldair, which cools an atmosphere in the vegetable compartment 13. Theremaining air in the first cold air producing chamber 36 is dischargedthrough the cold air discharge holes 40 of the cold air duct 41 and theopen upper end of the duct 41, then flowing into the cold air path 9below the chilling case 8. The air further flows through the deodorizer11 and the cold air path 101 into the vegetable compartment 13, furtherflowing through the holes 46 in front of the upper case 16. Thereafter,the interior air flows downward along the front of the lower case 16 andthen rearward along the underside of the lower case 15 to be returnedthrough the suction opening 38 into the first cold air producing chamber36. In this case, the interior air is cooled by the first evaporatorinto cold air, which cools an atmosphere in the cold storage compartment6 and the atmosphere in the vegetable compartment 13. More specifically,the deodorizer 52 is disposed at a return path side of the circulatedcold air.

[0051] A second cold air producing chamber 47 is provided in the rear ofthe freezing compartment 19. A cold air discharge opening 48 and a coldair suction opening 49 are provided in upper and lower ends of thesecond cold air producing chamber 47 respectively. The second evaporator34 and a second fan motor 50 are accommodated in the second cold airproducing chamber 47. The second fan motor 50 is connected through thedrive circuit 27 to the control device 28. The second fan 51 is coupledwith a rotational shaft of the fan motor 50 so that the cold air iscirculated through the following route upon rotation of the second fan51. A second fan unit 52 comprises the second fan motor 50 and thesecond fan 51. The second fan unit 52 and the second evaporator 34constitute a second cooling unit 53. Cold air circulation path for thefreezing compartment 6:

[0052] Interior air in the second cold air producing chamber 47 isdischarged through the cold air discharge opening 48 into the freezingcompartment 19 and returned through the cold air suction opening 49 intothe second cold air producing chamber 47. In this case, the interior airis cooled by the second evaporator 34 into cold air, which cools anatmosphere in the freezing compartment 19.

[0053] Referring now to FIG. 4, first and second temperature sensors 54and 55 are provided in the cold storage and freezing compartments 6 and19 respectively. The temperature sensors 54 and 55 comprise thermistorsdelivering temperature signals Vr and Vf with voltage levels accordingto temperatures in the cold storage and freezing compartments 6 and 19,respectively. The temperature sensors 54 and 55 are connected to thecontrol device 28. A first evaporator temperature sensor 56 and a secondevaporator temperature sensor 57 are connected to the control device 28.The first and second evaporator temperature sensors 56 and 57 comprisethermistors mounted on the first and second evaporators 33 and 34 usingfixtures (not shown), respectively. The first and second evaporatortemperature sensors 56 and 57 deliver temperature signals Vre and Vfehaving voltage levels according to surface temperatures of the first andsecond evaporators 33 and 34, respectively. First and second doorswitches 102 and 103 are provided for detecting an open or closed stateof the first and second doors 7 and 14 respectively. The signalsindicative of the open or closed states of the doors are supplied to thecontrol device 28.

[0054] The control device 28 includes an internal ROM on which anoperation control program is recorded. The control device 28 controlsthe compressor motor 26, the valve motor 31, and the first and secondfan motors 42 and 50 based on the temperature signals Vr, Vf, Vre andVfe form the first and second temperature sensors 54 and 55 and thefirst and second evaporator temperature sensors 56 and 57, whereby acooling operation is carried out. Further, the control device 28controls the high-voltage applying section (voltage changing means) 70so that a pulsed high voltage at minus several kilovolts is applied tothe electrodes of the deodorizer 11.

[0055] Referring to FIG. 1, a major part of the deodorizer 11 is shown.In a rectangular cylindrical blowing path 71 are disposed a prefilter72, an electrical discharge mechanism (discharging means) 73, twophotocatalyst modules 74 and an ozone decomposing catalyzer (ozonedecomposing means) 75. Cold air in the refrigerator is caused to flowthrough a left-hand inlet 71 a into the blowing path 71 upon rotation ofthe first fan 43 disposed in the first cold air producing chamber 36, asviewed in FIG. 1. The cold air then passes through the aforesaidelements so as to be deodorized. The deodorized cold air flows through aright-hand outlet 71 b into the cold air path 101 as viewed in FIG. 1.The prefilter 72 is disposed at the uppermost stream of the blowing path71 to remove dust from the cold air. The discharge mechanism 73 isdisposed next the prefilter 72 and comprises a plurality of generallywire-shaped discharge electrodes 76 made from tungsten and two flatcounter electrodes 77. The discharge electrodes 76 are disposed in onerow so as to extend horizontally across the flowing cold air. The twocounter electrodes 77 are disposed before and behind the dischargeelectrodes 76 with respect to the direction in which the cold air flows,so as to sandwich the discharge electrodes. Each counter electrode 77has a number of slits 77 a through which the cold air is caused to flow.A high voltage of the negative polarity is applied across the dischargeelectrodes 76 and the counter electrodes 77 so that ultraviolet rayseach having a wavelength not exceeding 380 nm and ozone are produced.

[0056] Each photocatalyst module 74 is provided between the dischargeelectrodes 76 and the counter electrodes 77. Each photocatalyst module74 comprises a base made from a porous ceramic such as alumina orsilica. A photocatalytic material such as titanium oxide is applied to asurface of the base and then dried or fired so as to be fixed to thesurface of the base. The discharge mechanism 73 is detachably attachedto the blowing path 71 in the direction of arrow in FIG. 1 together withthe photocatalyst modules 74. More specifically, an openable door (notshown) is mounted on a pipe wall of the blowing path 71 so as tocorrespond to a location of the discharge mechanism 73. When the door isopened, the discharge mechanism 73 and the photocatalyst modules 74 bothdisposed in the blowing path 71 are taken out in the direction of arrowin FIG. 1.

[0057] The operation of the refrigerator will now be described. A casewill first be described where the cooling operation is carried out onthe basis of information about a set temperature for the cold storagecompartment 6 and temperature information obtained by the firsttemperature sensor. In this case, the control device 28 opens the secondoutput port of the flow valve 30 so that the refrigerant discharged fromthe compressor 25 is supplied into the first evaporator 33. The controldevice 28 further drives the first fan unit 45 so that the cold air iscirculated through the cold storage and vegetable compartments 6 and 13.When the operation of the deodorizer 11 is then initiated, thehigh-voltage discharge is performed between the discharge electrodes 76and the counter electrodes 77 such that the ultraviolet rays and ozoneare produced.

[0058] The cold air containing odor component in the refrigerator flowsthrough the inlet 71 a into the deodorizer 11 as the result of rotationof the first fan 43. The cold air is then filtrated by the prefilter 72,thereafter reaching the discharge mechanism 73 through the slits 77 a ofthe counter electrodes 77. In the discharge mechanism 73, theultraviolet rays produced by the high-voltage discharge are irradiatedonto the photocatalyst modules 74. When subjected to light energy, thetitanium oxide is activated to perform the photocatalytic action.Consequently, the odor component contained in the circulated cold air,such as ammonia, is decomposed by oxidation. Furthermore, when passingthrough the discharge mechanism 73, the circulated cold air is mixedwith the ozone produced by the high-voltage discharge, reaching theozone decomposing catalyzer 75 disposed down the discharge mechanism 73with respect to the direction in which the circulated cold air flows.The ozone mixed with the odor component etc. in the circulated cold airis decomposed by the catalyzer 75 to thereby produce active oxygen. Theodor component etc. is decomposed by the active oxygen. The cold airthus deodorized in the aforesaid manner is recirculated through theoutlet 71 b into the compartments of the refrigerator.

[0059]FIG. 6 shows the results of an experiment conducted by theinventors. A remainder rate (%) of ammonia in the refrigerator withlapse of time was measured in the case where the ammonia in therefrigerator was decomposed by several types of deodorizers. Symbol “Δ”denotes the case of a conventional deodorizer of the heating type.Symbol “⋄” denotes the case of the deodorizer of the embodiment when theelectric discharge was carried out by the discharge mechanism 73 (ON).Symbol “◯” denotes the case of the deodorizer of the embodiment when theelectric discharge was not carried out by the discharge mechanism 73(OFF). As obvious from FIG. 6, even when the discharge mechanism wasturned off, the remainder rate of ammonia was reduced to a larger extentas compared with the case of the conventional deodorizer. A still moredesirable characteristic was obtained from the case of the deodorizer ofthe embodiment when the discharge mechanism was turned off.

[0060] According to the above-described embodiment, the deodorizer 11 isdisposed in the cold air path 101 of the refrigerator. The dischargemechanism 73, the photocatalyst modules 74 and the ozone decomposingcatalyzer 75 are disposed in the blowing path 71 of the deodorizer 11.The ultraviolet rays are produced by the high-voltage discharge of thedischarge mechanism 73. The ultraviolet rays cause the photocatalystmodules 74 to perform the photocatalytic action. Further, the ozoneresulting from the high-voltage discharge is decomposed by the ozonedecomposing catalyzer 75. Consequently, the odor component and injuriouscomponent are decomposed by oxidation. Thus, decomposition andelimination of the odor component etc. present in the refrigerator arecarried out using the ozone and ultraviolet rays both produced by thehigh-voltage discharge. Consequently, an adsorbent for deodorizationneed not be replaced by a new one, and drug need not be supplemented.Further, since the photocatalytic action and the ozone decomposingaction are combined together, a wider range of odor component can bedecomposed. Additionally, since the deodorizer 11 can produce theultraviolet rays without using a fluorescent lamp, no special handlingis required in the case of disposition of the refrigerator or thedeodorizer 11.

[0061] Further, since the deodorizer 11 decomposes the ozone by means ofthe ozone decomposing catalyzer 75, the ozonic concentration in theatmosphere in the cold storage or vegetable compartment 6 or 13 can beprevented from an excessive increase and accordingly, the user can beprevented from having a smell of ozone (in the concentration rangingbetween 0.02 and 0.03 ppm, for example) when opening the door 7 or 14 ofthe refrigerator or components in the interior of the refrigerator canbe prevented from corrosion.

[0062] Further, the discharge mechanism 73 is detachably attached to theblowing path 71. Accordingly, when contaminant is adherent to thedischarge electrodes 76, the counter electrodes 77 or the photocatalystmodules 74, the discharge mechanism 73 is detached from the deodorizerbody so that the contaminant is eliminated by water washing, forexample. Additionally, the discharge mechanism 73 comprises a pluralityof generally wire-shaped discharge electrodes 76 and two flat counterelectrodes 77. Accordingly, a larger space for deodorization can beobtained as compared with a surface discharge system in which electricdischarge is performed via an insulator. Further, since the high voltageof the negative polarity is applied across the discharge electrodes 76and the counter electrodes 77, a larger amount of ozone can be producedand accordingly, the deodorizing efficiency can be improved.

[0063] The voltage application to the discharge mechanism 73 issynchronized with the operation of the first fan 43. Further, thevoltage applied to the discharge mechanism 73 is changed according to avolume of air supplied by the first fan 43. Accordingly, deodorizationcan efficiently be performed in the case where the deodorizer 11 isoperated when the circulated cold air flows into the blowing path 71.The applied voltage is increased as the rotational speed of the firstfan 43 is decreased such that a flow rate of cold air is reduced.Consequently, a reduction in the deodorizing efficiency with thereduction in the flow rate of cold air can be compensated.

[0064] Since each photocatalyst module 74 is disposed between theelectrodes 76 and 77 of the discharge mechanism 73, non-directionalultraviolet rays produced by the discharge mechanism 73 can efficientlybe irradiated onto each photocatalyst module 74 and accordingly, theefficiency in the photocatalytic reaction can be improved. Furthermore,the photocatalyst modules 74 are disposed at the upstream and downstreamsides of the discharge mechanism 73. Consequently, the ultraviolet raysproduced in the discharge mechanism 73 can be used further efficiently.Additionally, each photocatalyst module 74 is formed by fixing titaniumoxide to the surface of the base made from the porous ceramic.Consequently, the flow of cold air can be prevented from being blockedby each photocatalyst module 74 even when each module is disposed in theblowing path 71. Further, since an area of the base surface to whichtitanium oxide is fixed is rendered larger, the photocatalytic reactioncan be performed with high efficiency even when an amount of titaniumoxide which is an expensive material is reduced as much as possible,whereupon the injurious matter can efficiently be eliminated.

[0065]FIG. 7 illustrates a second embodiment of the invention. Only thedifferences between the first and second embodiments will be described,and identical or similar parts in the second embodiment are labeled bythe same reference symbols as in the first embodiment. In the secondembodiment, the deodorizer 11 is disposed above the first fan 43 in thefirst cold air producing chamber 36 with the inlet 71 a being located atthe first fan 43 side. The ozone decomposing catalyzer 78 is disposed inthe cold air suction opening 38 of the first cold air producing chamber36. The other construction of the refrigerator is the same as that inthe first embodiment.

[0066] According to the second embodiment, ozone can be decomposed alsoat the cold air inlet 38 by the ozone decomposing catalyzer 78.Consequently, the first evaporator 33 and the other piping disposed inthe first cold air producing chamber 36 can reliably be prevented frombeing corroded by the ozone. In the construction of the secondembodiment, the ozone concentration is at or below 0.05 ppm in orderthat the corrosion may be prevented.

[0067]FIGS. 8, 9A and 9B illustrate a third embodiment. In the thirdembodiment, the deodorizer 11A is discrete from the refrigerator body 1.The deodorizer 11A is detachably attached to the refrigerator body 1.The deodorizer 11A is disposed in the cold air path 79 defined betweenthe lower case 15 and the heat-insulating partition plate 12 in thevegetable compartment 13 as shown in FIG. 8. The outlet 71 b of thedeodorizer 11A communicates with the cold air suction opening 38 of thefirst cold air producing chamber 36.

[0068] A power-supply plug 80 for supplying AC 100 V extends from theright-hand rear end of the deodorizer 11A as shown in FIG. 9A. When thedeodorizer 11A is attached to the refrigerator, the power-supply plug 80is inserted into a socket 81 provided by the side of the cold airsuction opening 38 as shown in FIG. 9B.

[0069] According to the third embodiment, the deodorizer 11A isdetachably attached to the refrigerator body 1. Accordingly, whencontaminant is adherent to the discharge electrodes 70, the counterelectrodes 77 or the photocatalyst modules 74, the discharge mechanism73 is taken out of the deodorizer body so that the contaminant isremoved by water washing etc. as in the first embodiment. For example,refrigerators for commercial use and for insulated vans have a largercapacity and accordingly, a large amount of odor component is containedin the interior atmosphere of the refrigerators. As a result,maintenance needs to be frequently carried out. Thus, when the inventionis applied to such a refrigerator having a large capacity, themaintenance can readily be performed.

[0070]FIGS. 10 and 11 illustrate a fourth embodiment. Only thedifferences between the first and fourth embodiments will be described.In the fourth embodiment, the deodorizer 11B includes a dischargemechanism (discharging means) 82 comprising a plurality of counterelectrode strips 83 (the number of discharge electrodes 76 plus one).The counter electrode strips 83 and the discharge electrodes 76 arealternately disposed so that flat sides of the strips are parallel toone another. Two photocatalyst modules 74 are disposed at the upstreamand downstream sides of the discharge mechanism 82 respectively. Thedischarge mechanism 82 is detachably attached to the blowing path 71.Each photocatalyst module 74 discrete from the discharge mechanism 82 isalso detachably attached to the blowing path 71.

[0071] The deodorizer 11B operates substantially in the same manner asthe deodorizer 11 in the first embodiment. In the fourth embodiment, thecounter electrodes 83 are disposed so that the flat sides thereof areparallel to one another. Consequently, the counter electrodes 83 do notprevent the cold air from flowing in the blowing path 71. Furthermore,when each photocatalyst module 74 having two sides A and B is attachedto the blowing path 71, the side A confronting the mechanism 82 side anda side B opposed to the side A are changeable with each other. Morespecifically, contaminant is easy to adhere to the side A of each module74 since the side A confronting the discharge mechanism 82 is subjectedto an active photocatalytic reaction. Accordingly, when each module 74is detached at a certain stage of adherence of contaminant and the sidesA and B are changed with each other before water washing, thephotocatalytic reaction can desirably be executed temporarily using theside B to which few contaminant is adherent.

[0072] According to the fourth embodiment, the side A confronting themechanism 82 side and a side B opposed to the side A are changeable witheach other when each photocatalyst module 74 is attached to thedeodorizer 11B. Even when the photocatalytic reaction is reduced with acertain amount of contaminant adherent to the side A, the photocatalyticreaction can temporarily be activated as the result of change of thesides A and B with each other. Thus the photocatalyst module 74 can beused more effectively.

[0073]FIG. 12 illustrates a fifth embodiment. Only the differencesbetween the first and fifth embodiments will be described. In the fifthembodiment, the deodorizer 11C includes a built-in blowing fan 84provided in the body thereof. The other construction of the deodorizeris the same as in the first embodiment. The fan 84 can be operatedindependently of the first fan 43. Accordingly, even when the operationof the first fan 43 is interrupted during the energy-saving operation ordefrosting operation of the refrigerator, the fan 84 is operated so thatthe deodorizer 11C performs the deodorizing operation. Additionally, thedeodorizer of the fifth embodiment can be applied to refrigerators ofthe direct-cooling system.

[0074]FIG. 13 illustrates a sixth embodiment. In the sixth embodiment,the deodorizer 85 can be powered by a battery. Accordingly, thedeodorizer 85 is operable independently of the refrigerator body 1. Morespecifically, the machine compartment 87 is defined below the blowingpath 86 as shown in FIG. 13. In the machine compartment 87 are encloseda high-voltage applying section 88 including a step-up transformer 88 a,batteries 89, an electric motor (DC motor) 90 for driving the blowingfan 84. The blowing path 86 has an upwardly directed outlet 86 b asviewed in FIG. 13. The blowing path 86 is thus formed into a generallyL-shape.

[0075] The high-voltage applying section 88 includes an AC convertingsection (not shown) for converting a DC power supply from the batteries89 to a corresponding AC which is stepped up by the step-up transformer88 a and then converted to a corresponding DC by a DC converting section(not shown) provided at a secondary side of the step-up transformer 88a. Finally, a pulsed high voltage of the negative polarity is appliedacross the discharge electrodes 76 and the counter electrodes 77 in thesame manner as in the first embodiment.

[0076] According to the sixth embodiment, the deodorizer 85 is driven bythe batteries 89 with the use of the step-up transformer 88a, whereuponthe deodorizer 85 is discrete from the refrigerator. Consequently, thedeodorizer 85 can be disposed at any location in the refrigerator, forexample, near food emitting a more offensive smell, such thatdeodorization can efficiently be performed. Further, when the deodorizer85 is disposed in a refrigerator without a deodorizing function,deodorization can be performed.

[0077] FIGS. 14 to 16 illustrate a seventh embodiment of the invention.In a duct-like blowing path 111 are disposed a prefilter 112, adischarge mechanism (discharging means) 113, two photocatalyst modules114 and an ozone decomposing catalyzer (ozone decomposing means) 115. Afan 116 is disposed in a right-hand end of the blowing path 111 asviewed in FIG. 14. Upon rotation of the fan 116, air in a room is causedto flow through the left-hand inlet 111 a into the blowing path 111 asviewed in FIG. 14. The air then passes through the aforesaid elements soas to be deodorized. The deodorized air is caused to exit through aright-hand outlet 111 b.

[0078] The prefilter 112 is disposed at the uppermost stream of theblowing path 111 to remove dust from the air. The discharge mechanism113 is disposed next the prefilter 112 and comprises a plurality ofgenerally wire-shaped discharge electrodes 117 made from tungsten etc.and two flat counter electrodes 118. The discharge electrodes 117 aredisposed in one row so as to extend horizontally across the flowing air.The two counter electrodes 118 are disposed before and behind thedischarge electrodes 76 with respect to the direction in which the airflows, so as to sandwich the discharge electrodes. Each counterelectrode 118 has a number of slits 118 a through which the air iscaused to flow.

[0079] Referring to FIG. 15, a control section 119 serving as thecontrol means controls the deodorizer and mainly comprises amicrocomputer (not shown). An operating section 120 includes a startswitch, a switch for setting an operational state such as wind speed(air flow rate), etc. These switches generate respective operationsignals, which are delivered to the control section 119. The controlsection 119 further controls the fan 116 and a high-voltage applyingsection 121 according to operation signals delivered thereto from theoperating section 120. The high-voltage applying section 121 comprises astep-up transformer in which a step-up ratio is variable. Thehigh-voltage applying section 121 applies a step-up pulsed DC voltage atminus several kilovolts to the discharge electrodes 117. The counterelectrode 118 are grounded. Ultraviolet rays each having a wavelengthnot exceeding 380 nm and ozone are produced by the high-voltagedischarge between the discharge electrodes 117 and the counterelectrodes 118. In this case, the control section 119 controls therotational speed of the fan 116 according the operation by the user sothat a flow rate of air caused to flow through the blowing path 111 iscontrolled and so that the voltage applied to the discharge electrodes117 is controlled according to a set air flow rate.

[0080] The photocatalyst modules 114 are disposed between the dischargeelectrodes 117 and the counter electrodes 118 respectively. Eachphotocatalyst module 114 comprises a base made from a porous ceramicsuch as alumina or silica. A photocatalytic material such as titaniumoxide is applied to a surface of the base and then dried or fired so asto be fixed to the surface of the base. The discharge mechanism 113 isdetachably attached to the blowing path 11 constituting the body of thedeodorizer together with the photocatalyst modules 114. Morespecifically, an openable door (not shown) is mounted on a pipe wall ofthe blowing path 111 so as to correspond to a location of the dischargemechanism 113. When the door is opened, the discharge mechanism 113 andthe photocatalyst modules 114 both disposed in the blowing path 111 aretaken out in the direction of arrow in FIG. 14.

[0081] The ozone decomposing catalyzer 115 includes a core and acatalyzing component fixed to the core. The core comprises a manganeseoxide-based ceramic honeycomb (a product) or is made by forming a metalhoneycomb into the shape of a rectangular plate. The catalyzer 115 withthe honeycomb structure provides a large area of contact with ozone orodor component, improving a decomposing efficiency.

[0082] The operation of the deodorizer will now be described mainly withreference to FIG. 16. When the user operates the start switch of theoperating section 120, the fan 116 is rotated and the high-voltageapplying section 121 is driven to apply the high voltage at minusseveral kilovolts to the discharge electrodes 117, under the control ofthe control section 119. As a result, the high-voltage discharge isperformed between the discharge electrodes 117 and counter electrodes118 so that ultraviolet rays and ozone are produced. In this case, aircontaining odor component in the refrigerator is caused to flow throughthe inlet 111 a into the blowing path 111 upon rotation of the fan 116.The air then passes through the prefilter 112 to be filtered, furtherflowing through the slits 118 a into the discharge mechanism 113. In thedischarge mechanism 113, the ultraviolet rays produced by thehigh-voltage discharge are irradiated onto the photocatalyst modules 114such that the titanium oxide is activated in subject to light energy ofthe ultraviolet rays thereby to perform the photocatalytic action. As aresult, odor component contained in the air, such as ammonia, NOx, andother organic matter and injurious matter such as formaldehyde aredecomposed by oxidation.

[0083] Furthermore, when passing through the discharge mechanism 113,air is mixed with ozone produced by the high-voltage discharge, furtherflowing into the ozone decomposing catalyzer 115. The ozone mixed withthe odor component in the air is decomposed by the catalyzer 115 suchthat active oxygen is produced. The odor component is oxidized by theactive oxygen thereby to be decomposed. The air deodorized as describedabove is caused to flow through the outlet 111 b into the room.

[0084] The control section 119 sets the step-up voltage in thehigh-voltage applying section 121 at about −7 kV (peak value) when aflow rate of air flowing through the path 111 is set at about 100 m³/hin the operating section 120, for example. When the flow rate of airflowing through the path 111 is set at about 50 m³/h, the controlsection 119 sets the step-up voltage at about −10 kV. The reason forthis setting is that when a flow rate of air treated by the deodorizeris reduced, the discharge voltage is increased for increase in thedeodorizing performance so that the deodorizing efficiency is preventedfrom being reduced.

[0085]FIG. 16 shows the results of an experiment conducted by theinventors. In the experiment, a test chamber with the capacity of 1m³was filled with 30 ppm of formaldehyde gas. The deodorizer of theseventh embodiment was placed in the test chamber to be operated. Therelative concentration of the formaldehyde gas was measured. As obviousfrom FIG. 16, the concentration of formaldehyde gas is reduced withprogress of gas removal by the operation of the deodorizer. FIG. 16shows that the relative concentration was reduced to 60 after 100minutes from the start of operation of the deodorizer.

[0086] According to the seventh embodiment, the discharge mechanism 113,the photocatalyst modules 114 and the ozone decomposing catalyzer 115are disposed in the blowing path 111 of the deodorizer. Thephotocatalyst modules 114 performs the photocatalytic action whensubjected to the ultraviolet rays produced by the high-voltage dischargeby the discharge mechanism 113, so that the ozone produced by means ofthe high-voltage discharge is decomposed by the catalyzer 115.Consequently, the odor component and injurious matter contained in theatmosphere are oxidized to be decomposed. Thus, decomposition andelimination of the odor component etc. present in the room are carriedout using the ozone and ultraviolet rays both produced by thehigh-voltage discharge. Consequently, an adsorbent for deodorizationneed not be replaced by a new one, and drug need not be supplemented.Further, since the photocatalytic action and the ozone decomposingaction are combined together, a wider range of odor component can bedecomposed. Additionally, since the deodorizer 11 can produce theultraviolet rays without using a fluorescent lamp, no special handlingis required in the case of disposition of the deodorizer 11.

[0087] Furthermore, the discharge mechanism 113 and the photocatalystmodules 114 are detachably attached to the blowing path 111.Accordingly, when contaminants are adherent to the discharge electrode117, counter electrodes 118, and photocatalyst modules 114, thedischarge mechanism 113 is taken out of the body of the deodorizer sothat the contaminants adherent to the these components are eliminated bywater washing, for example. Further, the discharge mechanism 113comprises the wire-shaped discharge electrodes 117 and the flat counterelectrodes 118, and the discharge is directly executed between theseelectrodes. Consequently, a larger space for deodorization can beobtained as compared with a surface discharge system in which electricdischarge is performed via an insulator. Further, since the high voltageof the negative polarity is applied across the discharge electrodes 117and 118, a larger amount of ozone can be produced and accordingly, thedeodorizing efficiency can be improved.

[0088] Further, the voltage applied to the discharge mechanism 113 ischanged according to a volume of air supplied by the fan 116.Accordingly, the applied voltage is increased as the rotational speed ofthe fan 116 is decreased such that a flow rate of air is reduced.Consequently, a reduction in the deodorizing efficiency with thereduction in the flow rate of air can be compensated.

[0089] Furthermore, since each photocatalyst module 114 is disposedbetween the electrodes 117 and 118 of the discharge mechanism 113, theultraviolet rays produced by the discharge mechanism 113 can efficientlybe irradiated onto each photocatalyst module 114 and accordingly, theefficiency in the photocatalytic reaction can be improved. Further, thephotocatalyst modules 114 are disposed at the upstream and downstreamsides of the discharge mechanism 113. Consequently, the ultraviolet raysproduced in the discharge mechanism 113 can be used further efficiently.

[0090] Additionally, each photocatalyst module 114 is formed by fixingtitanium oxide to the surface of the base made from the porous ceramic.Consequently, the flow of air can be prevented from being blocked byeach photocatalyst module 114 even when each module is disposed in theblowing path 111. Further, since an area of the base surface to whichtitanium oxide is fixed is rendered larger, the photocatalytic reactioncan be performed with high efficiency even when an amount of titaniumoxide which is an expensive material is reduced as much as possible,whereupon the injurious matter can efficiently be eliminated.

[0091]FIGS. 17 and 18 illustrate an eighth embodiment of the invention.In the eighth embodiment, a discharge mechanism (discharging means) 122is provided instead of the mechanism 113. Each of a plurality of counterelectrodes 123 whose number is equal to the number of dischargeelectrodes 117 plus one is formed into the shape of a rectangular plate.The discharge electrodes 117 and the counter electrodes 123 are disposedalternately so that flat faces of the counter electrodes 123 areparallel with the direction in which the air flows. The twophotocatalyst modules 114 are disposed at the upstream and downstreamsides of the discharge mechanism 122.

[0092] The discharge mechanism 122 is detachably attached to the blowingpath 111 in the same manner as the mechanism 113 in the firstembodiment. The photocatalyst module 114 discrete from the dischargemechanism 122 is also detachably attached to the path 111.

[0093] The operation of the deodorizer of the eighth embodiment isbasically the same as that in the seventh embodiment. Furthermore, sincethe flat faces of the counter electrodes 123 are parallel with thedirection in which the air is caused to flow, the flow of air throughthe blowing path 111 is prevented from being blocked.

[0094] Furthermore, in the eighth embodiment, when each photocatalystmodule 114 having two sides A and B is attached to the blowing path 111,the side A confronting the mechanism 122 side and a side B opposed tothe side A are changeable with each other. More specifically,contaminant is easy to adhere to the side A of each module 114 since theside A confronting the discharge mechanism 122 is subjected to an activephotocatalytic reaction. Accordingly, when each module 114 is detachedat a certain stage of adherence of contaminant and the sides A and B arechanged with each other before water washing, the photocatalyticreaction can desirably be executed temporarily using the side B to whichfew contaminant is adherent.

[0095] According to the eighth embodiment, the side A confronting themechanism 122 side and a side B opposed to the side A are changeablewith each other when each photocatalyst module 114 is attached to thedeodorizer 11B. Even when the photocatalytic reaction is reduced with acertain amount of contaminant adherent to the side A, the photocatalyticreaction can temporarily be activated as the result of change of thesides A and B with each other. Thus the photocatalyst module 114 can beused more effectively.

[0096] The invention should not be limited to the foregoing embodimentsand may be modified as follows. In the first embodiment, the sides A andB of each photocatalyst module 74 can be changed with each other in thesame manner as in the fourth embodiment. Further, the sides A and B ofeach photocatalyst module 114 in the seventh embodiment can also bechanged with each other in the same manner as in the seventh embodiment.

[0097] Although two photocatalyst modules 74 are disposed at theupstream and downstream s ides of the discharge mechanism 73, 82, 113 or122 respectively in the foregoing embodiments, only one module may bedisposed at either upstream or downstream side.

[0098] The voltage applied to the discharge electrodes 76 or 117 mayhave the positive polarity. The applied voltage should not be limited tothe pulsed voltage and may be a steady AC or DC voltage. Further, theapplied voltage may be set to be constant irrespective of a flow rate ofthe blowing path 71 or 111.

[0099] The control device 28 may interrupt the operation of thedeodorizer 11 when the first or second door 7 or 14 is opened. As aresult, the high-voltage discharge can be stopped when the user opensthe door 7 or 14 to take food out of the refrigerator. The dischargemechanism may be of the flat surface type depending upon a setdeodorizing capability. The counter electrode 77 or 118 may be meshed.The voltage applied to the discharge mechanism 73, 113 or 122 may bechanged according to a set deodorizing capability as well as accordingto a supplied air volume.

[0100] The foregoing description and drawings are merely illustrative ofthe principles of the present invention and are not to be construed in alimiting sense. Various changes and modifications will become apparentto those of ordinary skill in the art. All such changes andmodifications are seen to fall within the scope of the invention asdefined by the appended claims.

We claim:
 1. A refrigerator in which a deodorizer is provided in a cold air circulation path for deodorizing an atmosphere in the refrigerator, the deodorizer comprising discharging means for producing ozone and ultraviolet rays by means of high-voltage discharge and a photocatalyst module for decomposing an odor component and injurious matter contained in the atmosphere by means of photocatalyst.
 2. A refrigerator according to claim 1, wherein the deodorizer further comprises ozone decomposing means for decomposing the ozone produced by the discharging means, the ozone decomposing means being disposed at a downstream side of at least the discharging means and the photocatalyst module with respect to a direction in which the cold air flows.
 3. A refrigerator according to claim 2, further comprising a heat exchanger having a cold air inlet, wherein the ozone decomposing means is disposed in the cold air inlet of the heat exchanger.
 4. A refrigerator according to claim 1, wherein two photocatalyst modules are disposed at upstream and downstream sides of the discharging means with respect to a direction in which the cold air flows, respectively.
 5. A refrigerator according to claim 1, wherein the deodorizer includes a body and the photocatalyst module is attached to and detached from the body of the deodorizer.
 6. A refrigerator according to claim 5, wherein the photocatalyst module has a first side confronting the discharging means and a second side located opposite the first side, and the first and second sides of the photocatalyst module are replaced each with the other when the photocatalyst module is attached to the body of the deodorizer.
 7. A refrigerator according to claim 1, wherein the photocatalyst module includes a base made from a porous ceramic and a photocatalytic material fixed to a surface of the base.
 8. A refrigerator according to claim 1, further comprising control means for controlling the deodorizer so that the discharging means discharges electricity when cold air is circulated in the refrigerator.
 9. A refrigerator according to claim 1, wherein the deodorizer includes a fan for blowing against the discharging means and the photocatalyst module.
 10. A refrigerator according to claim 1, wherein the deodorizer includes a body, and the discharging means includes two electrodes between which electric discharge is directly performed and is attached to and detached from the body of the deodorizer.
 11. A refrigerator according to claim 1, wherein the discharging means includes a pair of electrodes across which a high voltage of a negative polarity is applied so that electric discharge is performed.
 12. A refrigerator according to claim 1, further comprising voltage changing means for changing a discharge voltage of the discharging means.
 13. A refrigerator according to claim 1, further comprising a door closing and opening an interior of the refrigerator and control means for controlling the deodorizer so that the discharging means interrupts electric discharge when the door is opened.
 14. A refrigerator according to claim 1, wherein the discharging means includes a pair of electrodes and the photocatalyst module is disposed between the electrodes of the discharging means.
 15. A refrigerator according to claim 1, further comprising a refrigerator body, wherein the deodorizer is attached to and detached from the refrigerator body.
 16. A refrigerator according to claim 15, wherein at least the discharging means of the deodorizer is powered by a battery.
 17. A deodorizer which is detachably attached to a body of a refrigerator so as to be located in a cold air circulation path for deodorizing an atmosphere in the refrigerator, the deodorizer comprising discharging means for producing ozone and ultraviolet rays by means of high-voltage discharge and a photocatalyst module for decomposing an odor component and injurious matter contained in the atmosphere by means of photocatalyst.
 18. A deodorizer according to claim 17, wherein at least the discharging means is powered by a battery.
 19. A deodorizer comprising: a blowing fan; discharging means for producing ozone and ultraviolet rays by means of high-voltage discharge, the discharging means being disposed in a blowing path through which air is caused to flow by the blowing fan; a photocatalyst module provided in the blowing path for decomposing an odor component and injurious matter contained in the atmosphere by means of photocatalyst; and ozone decomposing means provided in the blowing path for decomposing the ozone produced by the discharging means.
 20. A deodorizer according to claim 19, which further comprises a body and wherein the discharging means is attached to and detached from the body.
 21. A deodorizer according to claim 19, wherein the discharging means includes two electrodes between which electric discharge is directly performed.
 22. A deodorizer according to claim 19, wherein the discharging means includes a pair of electrodes across which a high voltage of a negative polarity is applied so that electric discharge is performed.
 23. A deodorizer according to claim 19, wherein voltage applied to the discharging means is changed according to an amount of air supplied by the blowing fan.
 24. A deodorizer according to claim 19, wherein the discharging means includes a pair of electrodes and the photocatalyst module is disposed between the electrodes of the discharging means.
 25. A deodorizer according to claim 19, wherein two photocatalyst modules are disposed at upstream and downstream sides of the discharging means in the blowing path respectively.
 26. A deodorizer according to claim 19, which further comprises a body and wherein the photocatalyst module is attached to and detached from the body.
 27. A deodorizer according to claim 26, wherein the photocatalyst module has a first side confronting the discharging means and a second side located opposite the first side, and the first and second sides of the photocatalyst module are replaced each with the other when the photocatalyst module is attached to the body of the deodorizer.
 28. A deodorizer according to claim 19, wherein the photocatalyst module includes a base made from a porous ceramic and a photocatalytic material fixed to a surface of the base. 